With development of touch sensing technologies, especially with wide use of electronic devices having touch sensing surfaces, touch-based man-machine interaction means are more diversified. For example, different operations are implemented by defining different touch gestures, which greatly facilitates control by a user on electronic devices by using a touch panel. Some touch gestures are widely used because the touch gestures comply with natural usage habits of a user, for example, a gesture that two fingers touch a screen and move close to each other corresponds to zooming out.